Method and apparatus for the ultrasonic cleaning of biofilm coated surfaces

Abstract

To treat body surfaces, such as the sinuses, which are coated with biofilms, the surface is irrigated and suctioned with a fluid which may contain a biocide or other chemical agent for disrupting the biofilm while ultrasonic energy is applied to the fluid barrier formed over the biofilm. Action of the fluid enhanced by the ultrasonic energy tends to remove sections of biofilm which are suctioned out of the site. An electrical field may also be applied to the biofilm to enhance the disruptive action. Apparatus for practicing this method to treat chronic rhinosinusitis comprises an elongated tube adapted to be inserted into sinus cavities through the nose or mouth. The tube includes a first lumen which feeds an irrigating fluid containing biocides and/or biofilm-disruptive chemicals to the treatment site and a second lumen which suctions fluid from the site. An ultrasound horn extends through the tube and its distal end introduces ultrasonic energy into the fluid layer overlying the biofilm. In an alternative embodiment, the tube includes a pair of electrodes which establish an electric field across the biofilm, accelerating degradation.

1 . The method of reducing a biofilm, comprising: 
 irrigating the biofilm with a fluid containing a biofilm-reducing agent;    suctioning the biofilm-reducing agent from the treatment area, so as to maintain a fluid layer of the fluid in contact with the biofilm area to be treated; and    inducing ultrasonic energy into the fluid layer.    
   
   
       2 . The method of  claim 1  wherein the biofilm is disposed on the surface of human tissue.  
   
   
       3 . The method of  claim 2  where the human tissue comprises a body cavity.  
   
   
       4 . The method of  claim 3  wherein the body cavity constitutes the sinus cavity.  
   
   
       5 . The method of  claim 4  further comprising introducing and removing the fluid and introducing the ultrasonic energy into the fluid layer through an elongated tube having its distal end disposed within the body cavity and its proximal end exterior of the body.  
   
   
       6 . The method of  claim 1 , further comprising: establishing an electric field across the biofilm directly or through the fluid layer.  
   
   
       7 . The method of  claim 4  wherein the biofilm-reducing agent is chosen from the group consisting of guaifenesin, dornase alfa or N acetylcysteine or a derivative thereof to simultaneously attack the biofilm matrix and reduce the mucous layer on the sinus lining.  
   
   
       8 . The method of reducing biofilm resident on human tissue comprising: 
 surrounding a section of the tissue coated with biofilm by a cavity having an open edge with a resilient gasket formed thereon;    introducing fluid containing a biofilm-reducing agent into the cavity;    suctioning excess fluid and biofilm residue from the cavity; and    applying ultrasonic energy into the fluid contained within the cavity to produce mechanical forces on the biofilm.    
   
   
       9 . The method of  claim 8  further comprising establishing an electric field across the biofilm or the fluid layering contact with the biofilm to further enhance biofilm-reductive action.  
   
   
       10 . The method of  claim 9  further comprising mechanically agitating the biofilm surface in contact with the fluid within the cavity by a mechanical instrument introduced into the cavity.  
   
   
       11 . Apparatus for treating biofilm covered tissue forming part of a cavity within a living body comprising: 
 an elongated tube adapted to be inserted into the body so that its distal end is disposed within the cavity and its proximal end is exterior of the body, the tube containing a first lumen for introducing fluid into the cavity and a second lumen for suctioning fluid from the cavity and an ultrasonic horn;    a first port for introducing fluid containing biofilm treatment reducing agents into the proximal end of the first lumen;    a second port at the proximal end of the tube for applying a suction force to the second lumen to suction fluid from the cavity; and    an ultrasonic generator connected to the proximal end of the ultrasonic horn so as to introduce ultrasonic energy from the distal end of the tube into fluid contained within the cavity.    
   
   
       12 . The apparatus of  claim 11  further including a pair of electrodes extending along the tube between the distal and the proximate end, and an electric generator for applying an electric potential to the proximal ends of the electrodes so as to create a field across the biofilm or the fluid in contact with the biofilm within the cavity.  
   
   
       13 . The apparatus of  claim 12  wherein the tube is manually deformable.  
   
   
       14 . The apparatus of  claim 11  further including: 
 a source of mechanical motion connected to the proximal end of the tube;    a biofilm abrading device supported on the distal end of the tube; and    an elongated member extending through the tube connecting said source of mechanical motion to said biofilm abrading device to impart motion to the abrading device relative to the tube.    
   
   
       15 . The apparatus of  claim 14  in which the mechanical motion is rotational.  
   
   
       16 . The apparatus of  claim 14  in which the mechanical motion is vibratory.  
   
   
       17 . The apparatus of  claim 11  in which the ultrasonic generator introduces energy into the proximal end of the first lumen.  
   
   
       18 . The apparatus of  claim 11  in which the distal end of the elongated tube is manually deformable.  
   
   
       19 . The apparatus of claim  111  in which the distal end of the elongated tube is removable from the proximal end for replacement purposes.